This invention relates generally to disposable body fluids absorbent articles such as disposable diapers, training pants and sanitary napkins and, more particularly, to such articles provided with means by which the used article is fastened in a rolled up condition thereof for disposal.
It is well known to provide disposable body fluids absorbent articles with a tape fastener adapted to fasten the used article in a rolled up condition for hygienic disposal thereof.
For example, Japanese Laid-Open Utility Model Application No. Sho58-22908 discloses a disposable diaper in which one end portion of an adhesive tape is fixed to the diaper backsheet and the free end portion extends outward beyond the diaper waist-line edge. After use, the diaper soiled with excretions may be rolled up with the backsheet outside toward the free end portion of the tape and then the diaper thus rolled up may be fastened by the free end portion.
In addition, Japanese Laid-Open Utility Model Application No. Hei6-77722 discloses a pull-on disposable diaper in which a tape fastener extending vertically of the diaper is fixed at its one end to an outer surface of the backsheet. This tape fastener is normally folded longitudinally thereof and may be unfolded in its actual use to extend outward beyond the waist-line edge of the waist-opening. In this manner, the soiled diaper may be fastened by the unfolded tape fastener in a rolled up condition thereof for disposal as with the diaper disclosed in the Japanese Laid-Open Utility Model Application No. Sho58-22908.
In the diaper disclosed in the Japanese Laid-Open Utility Model Application No. Sho58-22908, a long adhesive tape will result in a longer free end portion that extends outward beyond the waist line edge, interfering with comfortable wear of the diaper. Accordingly, it is difficult in practice to employ a relatively long adhesive tape.
In the case of the diaper disclosed in the Japanese Laid-Open Utility Model Application No. Hei6-77722, a longer adhesive tape will result in a more bulky tape when in a folded condition. Consequently, this folded adhesive tape may catch the baby""s eye and the baby may play with the tape. Once the adhesive tape has been unfolded by the baby, it is not easy to refold and, in consequence, a troublesome labor is forced upon the mother.
The problem common to both of the well known diapers mentioned is that, after the soiled diaper has been removed from the baby, rolled up and tightly fastened by the adhesive tape stretched with a high tension, the adhesive once anchored to the rolled diaper may often peel off from the outer surface of the rolled diaper under the tension of the adhesive tape unless the anchoring of the adhesive tape is reliably firm.
In view of the above problem, it is a principal object of the invention to provide a disposable body fluids absorbent article, such as a disposable diaper, with a relatively short tape fastener that allows the article to be easily held in its rolled up condition without the tape fastener peeling from the outer surface of the rolled article once the tape fastener has been anchored to the outer surface.
The object set forth above is achieved, according to the invention, with a disposable body fluids absorbent article comprising a topsheet on a skin-contactable side, a backsheet on a skin non-contactable side, and a tape fastener adapted to fasten the body fluids absorbent article soiled with excretions in a rolled up condition thereof in a predetermined direction.
The tape fastener comprises a fixed end portion secured to an outer surface of the backsheet and a free end portion longitudinally opposite to the fixed end portion which is adapted to be held by the user""s fingers. An elastically stretchable portion extends between the fixed and free end portions. An adhesive portion extends longitudinally between the free end portion and the elastically stretchable portion with an inner surface of the adhesive portion facing the outer surface of the backsheet releasable bonded to the outer surface.
In another aspect of the invention, the elastically stretchable portion comprises an elastically stretchable sheet having an elongation percentage in the longitudinal direction of 100-1500% and an elastic recovery percentage of 10-90% relative to the elongation percentage.
In another aspect of the invention, the fixed end portion, the free end portion and the adhesive portion are formed by sheet material substantially less stretchable than the elastically stretchable portion.
In yet another aspect of the invention, after the adhesive portion releasably bonded to the outer surface of the backsheet has been peeled off from the outer surface of the backsheet, the tape fastener can be longitudinally stretched until a portion of the tape fastener, at least including the free end portion and the adhesive portion, stretches past an outer edge of the rolled up body fluids absorbent article to reach a position lying outward beyond the outer edge.
The invention allows the tape fastener used to fasten the disposable body fluids absorbent article to be shortened sufficiently to avoid any concern that the tape fastener might prevent the article from being smoothly worn, since the tape fastener has appropriate stretchability. In addition, the tape fastener is not readily peeled off from the article which has been fastened in a rolled up condition thereof by the stretched tape fastener, since the contractile force of this tape fastener is progressively reduced as time elapses after the tape fastener has been stretched to fasten the rolled up article.
Other and further objects, features and advantages of the invention will appear more fully from the following description.